the system of terms belonging or peculiar to a science, art, or specialized subject; nomenclature

the terminology of botany.

the science of terms, as in particular sciences or arts.

noun

choice of words , diction , jargon , language , lingo , locution , nomenclature , onomastics , phraseology , phrasing , turn of phrase , vocabulary , wordage , words , argot , cant , dialect , idiom , lexicon , patois , vernacular